1. Field of the Invention
The present invention relates to a continuously variable transmission comprising a hydraulic pump and a hydraulic motor, for use in a small-size working machine such as a powered lawn mower or the like.
2. Description of the Prior Art
Conventional continuously variable transmissions comprising a hydraulic pump and a hydraulic motor for use in agricultural machines are disclosed in Japanese utility model publication No. 58-32984 and Japanese laid-open patent publication No. 64-4512.
In each of the disclosed continuously variable transmissions, the hydraulic pump and motor have their cylinders oriented such that the continuously variable transmission has input and output shafts extending perpendicularly to each other, the input shaft being coupled to the hydraulic pump and the output shaft to the hydraulic motor. The continuously variable transmission has a partition, a bearing, and other parts disposed between the cylinders of the hydraulic pump and motor. The hydraulic pump includes a swash plate for controlling the displacement thereof. The swash plate is movably supported by a support member which is fixed to the case of the continuously variable transmission.
While the input shaft coupled to the hydraulic pump and the output shaft coupled to the hydraulic motor extend perpendicularly to each other, as described above, the cylinders of the hydraulic pump and motor are spaced from each other because of the partition, the bearing, and other parts interposed therebetween. Therefore, the outer profile of the case of the continuously variable transmission is relatively large. Furthermore, the swash plate for controlling the pump displacement is supported by a complex structure including the support member described above.